1. Technical Field
The present disclosure relates to a positive electrode active material for nonaqueous electrolyte secondary batteries and a nonaqueous electrolyte secondary battery.
2. Description of the Related Art
Nonaqueous electrolyte secondary batteries need to have both high capacity and enhanced cycle characteristics. Therefore, a positive electrode, including a positive electrode core and a positive electrode active material layer placed thereon, for nonaqueous electrolyte secondary batteries needs to have high filling properties for high capacity and high durability for enhanced cycle characteristics.
WO 2014/103166 discloses that capacity density and cycle characteristics are improved in such a manner that the powder fracture strength of a positive electrode active material is adjusted to 300 MPa to 500 MPa and the grain size of the positive electrode active material is controlled to 100 nm to 300 nm.
However, in the case where a pressure of 500 MPa or more is applied to particles making up a positive electrode active material for the purpose of increasing the density of a positive electrode, the particles are cracked. A positive electrode active material with excellent cycle characteristics cannot be obtained.